Electrically charged products of photosynthesis, e.g. negatively charged carbonic
acids, would have been attracted by the complementary charges at the ZnS surfaces
of mineral compartments. These molecules could have interacted with each
other at the catalytic surfaces of continuously operating porous ZnS photoreactors,
yielding even more intricate carbon- and nitrogen-containing molecules.
The more complex molecules would, generally, have absorbed more light and
been more vulnerable to UV quanta. Still, in certain cases, the increase in chemical
complexity may have been accompanied by an increase in photostability. Indeed,
the destruction of a chemical compound by a light quantum starts with the
“trapping” of its energy by a particular chemical bond, followed by an increase
in the energy of this bond and its eventual dissociation [195]. However, if the
absorbed energy is spread over many bonds, then the probability of bond cleavage
drops dramatically. Such a spreading of excitation energy occurs in systems that
contain conjugated bonds (so-called π-systems with alternating single and double
bonds); the spreading is facilitated by a ring-like (aromatic) molecular structure.
All nucleobases belong to such ring-like, conjugated systems [159]; the lifetime of
their excited states (~100 fs [164]) is extremely short even for π-systems; this short
life time would additionally have decreased the probability of photodestruction.
As discussed above, the UV-resistance of π-systems could increase further upon
their stacking together and/or adsorption to radiation-absorbing minerals.
Electrically charged products of photosynthesis, e.g. negatively charged carbonicacids, would have been attracted by the complementary charges at the ZnS surfacesof mineral compartments. These molecules could have interacted with eachother at the catalytic surfaces of continuously operating porous ZnS photoreactors,yielding even more intricate carbon- and nitrogen-containing molecules.The more complex molecules would, generally, have absorbed more light andbeen more vulnerable to UV quanta. Still, in certain cases, the increase in chemicalcomplexity may have been accompanied by an increase in photostability. Indeed,the destruction of a chemical compound by a light quantum starts with the“trapping” of its energy by a particular chemical bond, followed by an increasein the energy of this bond and its eventual dissociation [195]. However, if theabsorbed energy is spread over many bonds, then the probability of bond cleavagedrops dramatically. Such a spreading of excitation energy occurs in systems thatcontain conjugated bonds (so-called π-systems with alternating single and doublebonds); the spreading is facilitated by a ring-like (aromatic) molecular structure.All nucleobases belong to such ring-like, conjugated systems [159]; the lifetime oftheir excited states (~100 fs [164]) is extremely short even for π-systems; this shortlife time would additionally have decreased the probability of photodestruction.ดังที่กล่าวไว้ข้างต้น ทน UV π-ระบบสามารถเพิ่มเติมเมื่อการซ้อนกันและ/หรือดูดซับการแผ่รังสีการดูดแร่ธาตุ
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